Police and election officials in Scotland have issued warnings to polling stations and local commanders after radical nationalists urged voters to photograph their ballot papers and follow ballot boxes to count centres on Thursday night.

Some pro-independence campaigners allege that last September’s independence referendum result was fixed – a claim repeatedly rejected by the Scottish National party leader, Nicola Sturgeon. Activists claim that voting in Thursday’s general election could also be rigged, in an effort to prevent SNP votes being properly counted.

Police and electoral officials placed the campaigners’ claims “in the context of conspiracy theories after the referendum” but are worried about the risks of trouble after recent tussles during nationalist protests at Labour election rallies in Glasgow.

Officials at City of Edinburgh council told the Guardian formal warnings were sent on Wednesday morning from Scotland’s electoral management board (EMB) to returning officers in all 32 local authorities to watch for queues forming and for any disruption or “threatening behaviour” at polling stations.

In an online campaign dubbed #OperationScallop, shared hundreds of times on Facebook and Twitter, activists have urged voters to wait until the final hour of polling on Thursday so they can track their ballot papers from polling stations to count centres, in an attempt to prevent them being tampered with.

A detailed advice sheet issued by the Twitter account for a Glasgow-based IT company Spectrum Systems urges them to photograph their voting papers, check that each ballot carries valid security markings and then watch them be correctly handled.

Contacted by the Guardian, Simon Lott, a director of Spectrum Systems, insisted their monitoring is intended to be peaceful and within the law: the campaign advice note to activists states they must not post any photographs before polling closes, not arouse police suspicions, and be “polite and courteous” if challenged. They must “comply with their legal requests without exception”.

But after taking advice from the Electoral Commission, polling station staff and police have also been told to ban voters from taking selfies or using cameras or smartphones in polling stations because it could be illegal.

The commission said there is no law explicitly banning photography in polling stations but it believes that sharing photographs of ballot papers is illegal, breaching the legal principle that voting must be secret. The commission did not concede that images of a ballot paper could be shared after polling closes.

Lott confirmed to the Guardian he planned to follow his ballot paper to the Glasgow election count at the Emirates arena on Thursday night. He would also amend his advice to fellow activists to alert them that the Electoral Commission advised it would be illegal to publish photographs of their ballot papers.

Lott said he believed his referendum ballot paper was a fake, and had failed to arrive at the count on 18 September. His complaints to the courts, the police, the Royal family and the security service had not been investigated, he said, and he had no confidence in Sturgeon’s assurances that the referendum was safe and legal.

“I will be watching my vote to make sure my vote gets to the count on time,” he said.

“All I want to do is have my eyes there to make sure my ballot paper gets into the box as per the law, gets handled and checked properly, gets loaded into the van as per the law, gets driven off by Labour council drivers in Labour council vans completely unsupervised for the next two hours and until they go to the Emirates. That gap needs to be supervised.”

Police Scotland has also circulated warnings and advice from the EMB to all divisional commanders, urging them to watch for queues forming after 9pm and to be aware of problems emerging in polling stations and on the roads after vans leave at 10pm with ballot boxes.

The notice states that police have been asked to be alert for any issues at polling stations. “That would include any threatening behaviour, either within polling places, outside them or during transit to the count.

“People are not encouraged and should not be allowed to take selfies, but obviously polling staff will need to make judgments about how or when they intervene with a view to their own safety and the efficient conduct of the poll.”

The official advice, passed to the Guardian, states: “This is all in the context of the various conspiracy theories after the referendum and of the general suspicion out there among certain sectors of the public. The police are aware of this campaign, as are the Electoral Commission.”

It adds: “With respect to following vans, the issue here is not one of electoral law but of laws with respect to the use of the public roads. The police should be involved if you have any concerns about the safety of your staff either in polling places, during the transport of boxes or at the count.”

The email repeats Electoral Commission advice that the law on taking selfies or photographs in polling booths is complex and depends on the circumstances of how a photograph is taken and what is done with it, but it urges polling staff to ban it entirely.

The advice states: “The law relating to voters taking photos of themselves in polling stations is complex and whether an offence has been committed would depend on a number of factors, including whether the photograph was shared with others and what the photograph showed.

“Given the risk that someone taking a photo inside a polling station may be in breach of the law, whether intentionally or not, our advice is that you should not allow photos to be taken inside polling stations.”

Sturgeon has repeatedly rejected complaints from within the yes movement that the referendum – which was set up by the Scottish government, was rigged. An SNP spokesman said they had no fears of any kind that the general election result would be undermined.

“We are entirely satisfied that the referendum was a gold standard in terms of the robustness of the democratic process, popular engagement, and a result which accurately reflected the votes of the people,” he said.

“And we are equally satisfied about all the arrangements for the general election, in which we hope that the people of Scotland will come together to elect a big team of SNP MPs to make Scotland stronger at Westminster and help deliver progressive policies for the whole of the UK.”

Ch Supt Jim Baird, the Police Scotland commander overseeing polling night operations, said: “We are aware of this. However, we will not comment on specific details of security arrangements.

“I would like to take this opportunity to assure the public that appropriate policing and security arrangements will be put in place to ensure the election process runs smoothly. The safety and security of the process is a top priority for Police Scotland and we have been liaising with the Electoral Commission and returning officers and will continue to do so throughout.”